Equip Weight above 100% of total Equip Load leaves the player unable to roll and run.
Trying to roll or backstep at this weight will stun the character.
Equip weight above 50% and up to 100% of Equip Load gives slow movement, and causes the player to 'fat roll'.
Equip weight above 25% and up to 50% of Equip Load gives medium movement.
There are also two different speeds to medium rolls, above and below 37.5%.
Equip weight equal to and below 25% of Equip Load gives fast movement.
Equip weight below 25% also has 4 individual speeds:
The fastest speed is achieved at 0% equip. The only weapons with no weight are Dragon Body and the Pyromancy Flame.
The other speed ranges are from 0.1% to 8.3%, 8.4% to 16.6%, and 16.7% to 25%.